1. Field of the Invention
This invention relates to boring bars for supporting machine tools, and more particularly to a boring bar assembly providing for cooling a tool during cutting and constructed for safety in operation and reduction of cutting tool breakage and damage to the parts being machined.
2. Brief Description of the Prior Art
In the machining of metal pieces with boring bars, it is important to be able to replace cutting tool inserts quickly and efficiently with a minimum amount of time lost in the repositioning and realignment operation. It is also very important to reduce the amount of tool breakage and the amount of material scrapped or destroyed by the cutting tool becoming dull or by the tool digging into the workpiece.
There are several patents which disclose boring bars and boring bar assemblies.
Jones, U.S. Pat. No. 2,333,935 discloses a cutting bar assembly for cutting internal grooves.
Johnson, U.S. Pat. No. 2,520,639 discloses another grooving tool having a rotary head portion.
Cogsdill, U.S. Pat. No. 3,195,378 discloses another boring tool.
Vassalo, U.S. Pat. No. 3,298,254 discloses a boring or grooving tool with replaceable cutters.
Proska, U.S. Pat. No. 3,344,690 discloses a boring bar assembly which comprises a shank piece and a head piece joined thereon. A telescoping tapered joint provides accurate centering of the head piece on the shank piece and manual removal of the head piece from the shank piece.
Lutz, U.S. Pat. No. 3,381,553 discloses an adjustable boring bar having a slot at one end and an adjustment means carried by the bar within the slot to flex the tip of the cutting element for radial adjustment.
Barkley, U.S. Pat. No. 4,063,843 discloses an adjustable boring bar assembly having first and second members telescopically engaged in a non-rotatable relation from one to the other. An adjustable abutment means is mounted on one of the members which when rotated provides relative axial movement between the first and second members.
Lovendahl, U.S. Pat. No. 4,164,381 discloses a boring bar assembly with an externally mounted cutting assembly.
Heaton et al, U.S. Pat. No. 4,197,771 discloses a quick change device for mounting a cutting tool in a support member. The tool has a shank with radially outward movable balls therein and includes an actuator ball causing the aforementioned balls to move outwardly and engage a shoulder at the end of a sleeve to pull and lock the tool into a predetermined axial position while cooperating key means in the tool and support member prevent rotation of the tool in the support member.
Eysel et al, U.S. Pat. No. 4,224,846 discloses a boring bar assembly comprising a tool support member which may carry one or more flexible cutting tools. The cutting tools may be expanded radially outward by a set of hydraulically operated pistons.
Eckle et al, U.S. Pat. No. 4,306,473 discloses a tool insert for a boring bar comprising a housing which can be inserted in a recess on a boring bar and which has a cutting tip slidably mounted in a longitudinal bore.
The prior art in general, and none of these patents in particular, disclose a boring bar assembly providing for cooling a tool during cutting and constructed for safety in operation and reduction of cutting tool breakage and damage to the parts being machined.